Lubricant with nanoparticulate additive

ABSTRACT

An engine oil additive includes carbon nanotubes and boron nitride particulates dispersed within a fluid. The additive is configured to be mixed with a quantity of oil such that the quantity of oil has a concentration from 0.05 to 0.5 grams of carbon nanotubes and of boron nitride particulates per quart of oil to improve the lubricity of the oil. The additive improves the horsepower and torque of the engine while reducing fuel consumption. The carbon nanotubes have an —OH functionalized exterior surface. The carbon nanotubes have a diameter from 1 nanometer to 50 nanometers and have a length from 1 micron to 1000 microns. The boron nitride particulates are hex-boron nitride structures having an average size from 30 nanometers to 500 nanometers.

CROSS-REFERENCES TO OTHER APPLICATIONS

This application claims priority to U.S. provisional patent applicationSer. No. 63/039,862, for “LUBRICANT WITH NANOPARTICULATE ADDITIVE” filedon Jun. 16, 2020 which is hereby incorporated by reference in entiretyfor all purposes.

This invention was made with Government support under FA8649-20-9-9046awarded by the United States Air Force Small Business InnovationResearch/Small Business Technology Transfer Center of Excellence. TheGovernment has certain rights in the invention.

BACKGROUND

Currently there are a wide variety of engines, transmissions andtribolological applications that employ a lubricant to reduce frictionbetween surfaces. New lubricants having an increased lubricity areneeded to reduce wear, reduce heat generation and reduce powerconsumption of these devices.

SUMMARY

In some embodiments a fluid comprises an oil, carbon nanotubes, andboron nitride particulates. In various embodiments the fluid has aconcentration from 0.01 to 1 gram of carbon nanotubes per quart of oil.In some embodiments the fluid has a concentration from 0.01 to 1 gram ofboron nitride particulates per quart of oil. In various embodiments thefluid has a concentration from 0.05 to 0.5 grams of carbon nanotubes perquart of oil. In some embodiments the fluid has a concentration from0.05 to 0.5 grams of boron nitride particulates per quart of oil. Invarious embodiments the carbon nanotubes have a functionalized exteriorsurface. In some embodiments the carbon nanotubes have a diameter from 1nanometer to 50 nanometers and have a length from 1 micron to 1000microns. In various embodiments the boron nitride particulates arehex-boron nitride structures having an average size from 30 nanometersto 500 nanometers.

In some embodiments a concentrate comprises a fluid, carbon nanotubesdispersed within the fluid and boron nitride particulates dispersedwithin the fluid. In various embodiments the concentrate is configuredto be added to a predetermined quantity of oil such that thepredetermined quantity of oil has a concentration of 0.05 to 0.5 gramsof carbon nanotubes per quart of oil. In some embodiments theconcentrate is configured to be added to a predetermined quantity of oilsuch that the predetermined quantity of oil has a concentration of 0.05to 0.5 grams of boron nitride particulates per quart of oil. In variousembodiments the carbon nanotubes have a functionalized exterior surface.In some embodiments the carbon nanotubes have a diameter from 1nanometer to 50 nanometers and have a length from 1 micron to 1000microns. In various embodiments the boron nitride particulates arehex-boron nitride structures having an average size from 30 nanometersto 500 nanometers.

In some embodiments an engine oil additive comprises a fluid, carbonnanotubes dispersed within the fluid and boron nitride particulatesdispersed within the fluid. In various embodiments the engine oiladditive is configured to be mixed with a quantity of oil such that thequantity of oil has a concentration from 0.05 to 0.5 grams of carbonnanotubes per quart of oil. In some embodiments the engine oil additiveis configured to be mixed with a quantity of oil such that the quantityof oil has a concentration from 0.05 to 0.5 grams of boron nitrideparticulates per quart of oil. In some embodiments the carbon nanotubeshave a functionalized exterior surface. In various embodiments thecarbon nanotubes have a diameter from 1 nanometer to 50 nanometers andhave a length from 1 micron to 1000 microns. In some embodiments theboron nitride particulates are hex-boron nitride structures having anaverage size from 30 nanometers to 500 nanometers.

Numerous benefits are achieved by way of the present invention overconventional techniques. For example, embodiments of the presentinvention reduce the coefficient of friction between two surfaces. Whenthe lubricating oil of an engine is modified with the carbon nanotubesand boron nitride particulates the engine generates increased power andincreased torque while reducing fuel consumption. These and otherembodiments of the invention along with many of its advantages andfeatures are described in more detail in conjunction with the text belowand attached figures.

To better understand the nature and advantages of the presentdisclosure, reference should be made to the following description andthe accompanying figures. It is to be understood, however, that each ofthe figures is provided for the purpose of illustration only and is notintended as a definition of the limits of the scope of the presentdisclosure. Also, as a general rule, and unless it is evident to thecontrary from the description, where elements in different figures useidentical reference numbers, the elements are generally either identicalor at least similar in function or purpose.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a non-scaled rendering of a nanomaterial modified oil thatincludes carbon nanotubes and boron nitride nanoparticulates dispersedwithin a lubricious fluid, according to an embodiment of the disclosure;

FIG. 2A illustrates a table of test results from six differentmotorcycles that were tested with and without the nanomaterial modifiedoil of FIG. 1;

FIG. 2B illustrates a table of coefficient of friction test results froma micro-friction and wear pin-on-disk test apparatus using thenanomaterial modified oil of FIG. 1;

FIG. 2C illustrates a table of friction testing from an ASTM G77Block-on-Ring test apparatus using the nanomaterial modified oil of FIG.1;

FIG. 2D illustrates a table showing oil temperature data during engineoperation using the nanomaterial modified oil of FIG. 1; and

FIG. 3 illustrates a table showing friction test data related todifferent degrees of —OH functionalization and geometries for carbonnanotubes dispersed within a lubricious fluid, according to embodimentsof the disclosure.

DETAILED DESCRIPTION

Techniques disclosed herein relate generally to lubricants. Morespecifically, techniques disclosed herein relate to lubricious oils thatcontain a combination of nanomaterial particulates for reducing frictionin engines and other types of machinery. Various inventive embodimentsare described herein, including methods, processes, systems, devices,and the like.

In order to better appreciate the features and aspects of the presentdisclosure, further context for the disclosure is provided in thefollowing section by discussing one particular implementation of anengine oil lubricant containing carbon nanotubes and boron nitridenanoparticulates, according to embodiments of the disclosure. Theseembodiments are for explanatory purposes only and other embodiments mayemploy other combinations of lubricious materials that may be used fordifferent purposes. For example, embodiments of the disclosure can beused with any lubricant that is configured to reduce friction betweentwo surfaces such as a grease or tribological coating.

FIG. 1 illustrates an artistic non-scaled rendering of a nanomaterialmodified oil 100 that is a combination of carbon nanotubes 105 and boronnitride nanoparticulates 110 dispersed within a lubricious fluid 115,according to embodiments of the disclosure. As shown in FIG. 1, aplurality of carbon nanotubes 105 are intermingled with a plurality ofboron nitride nanoparticulates 110. It will be appreciated that theorientation of carbon nanotubes 105 and boron nitride nanoparticulates110 may be different than illustrated in FIG. 1. In one embodimentlubricious fluid 115 is an oil designed to be a lubricant for aninternal combustion engine, however other embodiments can use differentlubricious fluids.

Carbon Nanotubes

Carbon nanotubes 105 can have any suitable shape or concentration. Insome embodiments the carbon nanotubes 105 can have a diameter between 1nanometer to 50 nanometers and can have a length from 1 micron to 1000microns. In one embodiment carbon nanotubes 105 are multi-wallednanotubes having a diameter between 20 nanometers and 40 nanometers anda length that is between 10 microns and 30 microns. In one embodimentcarbon nanotubes 105 have a diameter between 1 and 2 nanometers and alength that is between 1.5 and 2.5 microns. In other embodiments thenanotubes can be single-walled, double-walled or a combination of any ofsingle-walled, double-walled and/or multi-walled including up to 20 ormore walls.

In some embodiments all, or a portion of carbon nanotubes 105 can have afunctionalized surface. In one embodiment the functionalized surfaceincludes, but is not limited to: —OH, —COOH, ═O, —F, —Cl, —NH—R, —NH2,—OR, —P or any combination capable of hydrogen bonding. In oneembodiment carbon nanotubes 105 have a functionalized OH surface thatmay form hydrogen bonds between the carbon nanotubes and the boronnitride nanoparticulates 110. The hydrogen bonds can increase thethermal conductivity and electrical conductivity of the nanomaterialmodified oil 100 and may also improve the lubricity. As would beappreciated by one of skill in the art with the benefit of thisdisclosure, other surface modifications of the carbon nanotubes can beused to modify the way in which the carbon nanotubes interact with boronnitride particulates 110 and/or with lubricious fluid 115, and arewithin the scope of this disclosure.

Boron Nitride Nanoparticulates

Boron nitride nanoparticulates 110 can have any suitable shape orconcentration. In one embodiment boron nitride nanoparticulates 110 arehex-boron nitride structures and have an average particle size ofapproximately 70 nanometers. In other embodiments the average particlesize can be between 10 nanometers and 10,000 nanometers, while infurther embodiments the average particle size can be between 30nanometers and 500 nanometers and in some embodiments can be between 50and 90 nanometers.

In further embodiments any structure of boron nitride can be usedincluding a hexagonal structure in the form of a sheet rolled on itself,similar to that of carbon nanotubes. Other boron nitride structures suchas amorphous, cubic (c-BN) and wurtzite (w-BN) can be used.

Lubricious Fluid

Lubricious fluid 115 can be any suitable natural or synthetic oil, orblend thereof. Natural sources of base oils for lubricious fluid 115include hydrocarbon oils of lubricating viscosity derived frompetroleum, tar sands, coal, shale, and so forth, as well as natural oilssuch as rapeseed oil, and the like. Synthetic base stocks include, forexample, poly-α-olefin oils (PAO, such as hydrogenated or unhydrogenatedα-olefin oligomers), hydrogenated polyolefins, alkylated aromatics,polybutenes, alkyl esters of dicarboxylic esters, complex esters ofdicarboxylic esters, polyol esters, polyglycols, polyphenyl ethers,alkyl esters of carbonic or phosphoric acids, polysilicones,fluorohydrocarbon oils, and mixtures thereof. The poly-α-olefins may,for example, be oligomers of branched or straight chain α-olefins havingfrom 2 to 16 carbon atoms, specific examples being polypropenes,polyisobutenes, poly-1-butenes, poly-1-hexenes, poly-1-octenes andpoly-1-decene. Included are homopolymers, interpolymers and mixtures.

In one embodiment, mineral oil base stocks are used, such as, forexample, conventional and solvent-refined paraffinic neutrals and brightstocks, hydrotreated paraffinic neutrals and bright stocks, naphthenicoils, cylinder oils, and so forth, including straight run and blendedoils. In one more particular embodiment, synthetic base stocks can beused such as, for example, blends of poly-α-olefins with syntheticdiesters in weight proportions (PAO:ester) ranging from about 95:5 toabout 50:50.

The base oils will normally, but not necessarily always, have aviscosity range of SAE 0 to about SAE 250, and more usually about SAE 0to about SAE 50. The viscosity ranges can also be multi-viscosity rangessuch as, but not limited to 5W-30, 0W-40, 15W-40, etc.

Base stock oils suitable for use in the present invention may be madeusing a variety of different processes including but not limited todistillation, solvent refining, hydrogen processing, oligomerisation,esterification, and re-refining. For instance, poly-α-olefins (PAO)include hydrogenated oligomers of an α-olefin, the most importantmethods of oligomerisation being free radical processes, Zieglercatalysis, and cationic, Friedel-Crafts catalysis.

Certain of these types of base oils may be used for the specificproperties they possess such as biodegradability, high temperaturestability, or non-flammability. In other compositions, other types ofbase oils may be preferred for reasons of availability or lower cost.Thus, the skilled artisan will recognize that while various types ofbase oils discussed above may be used in the lubricant compositions ofthis invention, they are not necessarily equivalents of each other inevery application. In some embodiments lubricious fluid may be alubricant commonly known as a synthetic blend, a full-synthetic or anon-synthetic engine oil.

Nanomaterial Concentrations

A predetermined quantity of carbon nanotubes 105 and boron nitridenanoparticulates 110 can be added to a predetermined quantity oflubricious fluid 115 to provide a final desired concentration of carbonnanotubes and boron nitride nanoparticulates for a particularapplication. In one embodiment the final concentration can be 0.08 gramsof carbon nanotubes 105 and 0.08 grams of boron nitride nanoparticulates110 per quart of lubricious fluid 115. In further embodiments additionalreductions in engine friction can be experienced using a finalconcentration of 0.16 grams of carbon nanotubes 105 and 0.16 grams ofboron nitride nanoparticulates 110 per quart of lubricious fluid 115. Inyet further embodiments a final concentration of 0.24 grams of carbonnanotubes 105 and 0.24 grams of boron nitride nanoparticulates 110 perquart of lubricious fluid 115 can be used.

The concentrations described above are for example only and othersuitable concentrations are within the scope of this disclosure. In someembodiments a final concentration of carbon nanotubes 105 within a quartof lubricious fluid 115 can be between 0.01 gram and 1 gram. In otherembodiments the concentration of carbon nanotubes 105 can be between0.05 and 0.5 grams and in some embodiments the concentration can bebetween 0.07 and 0.17 grams per quart of lubricious fluid 115.

In some embodiments a final concentration of boron nitridenanoparticulates 110 within a quart of lubricious fluid 115 can bebetween 0.01 gram and 1 gram. In other embodiments the concentration ofboron nitride nanoparticulates 110 can be between 0.05 and 0.5 grams andin some embodiments the concentration can be between 0.07 and 0.17 gramsper quart of lubricious fluid 115.

In further embodiments the final concentration of carbon nanotubes 105and boron nitride nanoparticulates 110 within lubricious fluid 115 maynot be equal. In some embodiments the concentration of boron nitridenanoparticulates 110 may be greater than the concentration of carbonnanotubes 105 by 1.5 times to 50 times while in other embodiments it canbe between 2 times and 25 times and in some embodiments can be between 3times and 10 times the concentration of carbon nanotubes.

In some embodiments the concentration of carbon nanotubes 105 may begreater than the concentration boron nitride nanoparticulates 110 by 1.5times to 50 times while in other embodiments it can be between 2 timesand 25 times and in some embodiments it can be between 3 times and 10times the concentration of boron nitride nanoparticulates.

Concentrated Additive

In some embodiments nanomaterial modified oil 100 can be formulated as aconcentrated additive that can be added to a predetermined quantity oflubricious fluid 115 or other fluid that does not have the carbonnanotube or boron nitride nanoparticulates. Thus, after adding theconcentrated additive to the predetermined quantity of oil, theresulting mixture has a final desired concentration of carbon nanotubesand boron nitride nanoparticulates, as described above. In such a way,with each oil change a predetermined amount of the concentrated additivecan be added to the newly added oil to provide the engine with thedesired level of horsepower, efficiency, torque and/or otherimprovements in engine performance.

As an illustrative non-limiting example, a concentrated additive caninclude between 3.5 percent and 4.5 percent by weight each of carbonnanotubes 105 and boron nitride nanoparticulates 110. More specifically,in one example the concentrated additive can include 200 grams of carbonnanotubes 105 and 200 grams of boron nitride nanoparticulates 110 thatare dispersed within 5000 grams of lubricious fluid 115 such that thecarbon nanotubes and the boron nitride nanoparticulates are each 3.7percent of the total weight of the concentrated additive. In otherembodiments the weight percent of the carbon nanotubes can be between 2percent and 20 percent and the weight percent of the boron nitridenanoparticulates can be between 2 percent and 20 percent of theconcentrated additive. In some embodiments the concentration of thecarbon nanotubes may not be the same as the concentration of boronnitride nanoparticulates, as described above. In further embodiments thequantity of carbon nanotubes 105 and boron nitride nanoparticulates 110that are in the concentrated additive can be predetermined to yield afinal concentration of 0.08 grams per quart of lubricious fluid, orother concentrations as described above.

Benefits of Nanomaterial Oil

Nanomaterial modified oil 100 can improve engine efficiency by reducingfriction and increasing thermal conductivity. Nanomaterial modified oil100 can also provide an extended lifetime of internal engine componentsand provide fuel savings. The addition of a combination of carbonnanotubes 105 and boron nitride nanoparticulates 110 has demonstratedunexpected results, with improvements in performance beyond what wasexpected with the addition of carbon nanotubes or boron nitridenanoparticulates alone.

Fuel Efficiency Tests

Fifteen test vehicles ranging from 1990 to 2020 model years of variousmakes and types were tested using nanomaterial modified oil 100. Driversreported improved starts, noticeable power increase, and up to 12percent better fuel economy.

A Briggs and Stratton CR950 engine was tested using nanomaterialmodified oil 100 with different concentrations of the nanomaterials.Engine tear down revealed no measurable wear. The results are summarizedbelow:

-   -   2100 RPM        -   14 g of the additive yielded a 4.3 percent increase in            efficiency compared to oil without the additive.    -   2600 RPM        -   7 g of additive increased efficiency the most with an            improvement of 13.57 percent.        -   14 g of additive yielding a performance increase of 13.47            percent        -   28 g of additive improved performance by 5.25 percent.    -   3000 RPM        -   14 g of additive has a 21.6 percent improvement over the            base oil,        -   28 g solution had a positive increase of about 12.22            percent.

Horsepower and Torque Tests

FIG. 2A illustrates a table of test results from six differentmotorcycles A-F that were tested with and without the nanoparticulateadditive. As shown in FIG. 2A each test bike A-F demonstratedimprovements in maximum power and maximum toque with the additive. Insome cases the additive resulted in an improvement of approximately 11percent in maximum power and nearly 12 percent in maximum torque.

Coefficient of Friction Tests

FIG. 2B shows coefficient of friction results from a controlledatmosphere micro-friction and wear tester pin-on-disk setup at roomtemperature with a load of 200 g at three different rotational speeds of1000 rpm, 2000 rpm, and 3000 rpm for 60 minutes with 0.2 milliliters ofnanomaterial modified oil added to the surface every 6 minutes. Theresults show a significant improvement over the test standard of Mobil®Delvac® 1 ESP motor oil. A ratio of 45-parts Mobil® oil to 1-partnanomaterial modified oil significantly decreases the frictioncoefficient at any rpm compared to the Mobil® oil alone. In this testthe 45:1 ratio is equivalent to 0.08 grams of carbon nanotubes and 0.08grams of boron nitride nanoparticulates dispersed within 1 quart oflubricious fluid.

This 45:1 ratio provides a 15.5 percent friction reduction over Mobil®motor oil at 1000 rpm, a 33.3 percent friction reduction at 2000 rpmand, a 69.6 percent friction reduction at 3000 rpm. Oil additive at a9:1 ratio provides a 79.6 percent friction reduction over Mobil® motoroil at 1000 rpm and a 75.0 percent friction reduction at 2000 rpm. Thisratio may be more beneficial for lower rpm diesel engines, while theless concentrated ratios may be better for higher revving gasolineengines. The combination of the hexagonal boron nitride sheets andcarbon nanotubes provides an even greater reduction in frictioncoefficient than either the carbon nanotubes or the boron nitridenanoparticles alone.

FIG. 2C shows another example of friction testing using ASTM G77Block-on-Ring testing. The nanomaterial modified oil showed an averagecoefficient of friction that was 5.53 percent lower than that of theMobil® 1 base oil. In this test the 0.08 grams of carbon nanotubes and0.08 grams of boron nitride nanoparticulates were dispersed within 1quart of lubricious fluid.

Oil Temperature Tests

FIG. 2D shows a table that contains oil temperature data during engineoperation. The average oil temperature is given for each incrementalamount of concentrated additive. The average temperature increased withthe oil additive due to the increased thermal conductivity and/or heatcapacity of the oil and its ability to transfer heat from the enginecomponents. In this test, the amount of concentrated oil additive wasincrementally increased from 0 grams to 28 grams. In this test 7 gramsof the concentrated oil additive resulted in a final concentration of0.08 grams of carbon nanotubes and 0.08 grams of boron nitridenanoparticulates per 1 quart of lubricious fluid. With the addition ofan oil cooler it is anticipated the oil temperature would dropconsiderably when compared to the normal oil temperature.

Degree of —OH Functionalization and CNT Geometry

FIG. 3 shows a table that contains friction test data related todifferent degrees of —OH functionalization and geometries for carbonnanotubes. As shown in FIG. 3, the carbon nanotube diameters vary from 1nm to 80 nm. All of the multi wall nanotubes had the same length rangeof 10-30 μm. As also shown in FIG. 3, the hydroxyl (OH) groupconcentration varies from 0.76 percent to 3.96 percent.

All variations that include carbon nanotubes produced a lowercoefficient of friction when compared to commercial full syntheticMobil® 1 engine oil. The results also indicate that a higher degree of—OH functionalized may not be needed in order to obtain the highestperformance. More specifically, in some embodiments the —OHfunctionalization percentage can be between 0.5 percent to 10 percent,and in some embodiments is between 1 percent and 3 percent and invarious embodiments is between 1.2 percent and 2 percent.

In some embodiments the carbon nanotubes are multi-walled nanotubes witha diameter from 20 to 40 nanometers, a length from 10 to 30 microns, an—OH content of approximately 1.6 percent and a purity of greater than 97percent.

In the foregoing specification, embodiments of the disclosure have beendescribed with reference to numerous specific details that can vary fromimplementation to implementation. The specification and drawings are,accordingly, to be regarded in an illustrative rather than a restrictivesense. The sole and exclusive indicator of the scope of the disclosure,and what is intended by the applicants to be the scope of thedisclosure, is the literal and equivalent scope of the set of claimsthat issue from this application, in the specific form in which suchclaims issue, including any subsequent correction. The specific detailsof particular embodiments can be combined in any suitable manner withoutdeparting from the spirit and scope of embodiments of the disclosure.

Additionally, spatially relative terms, such as “bottom or “top” and thelike can be used to describe an element and/or feature's relationship toanother element(s) and/or feature(s) as, for example, illustrated in thefigures. It will be understood that the spatially relative terms areintended to encompass different orientations of the device in use and/oroperation in addition to the orientation depicted in the figures. Forexample, if the device in the figures is turned over, elements describedas a “bottom” surface can then be oriented “above” other elements orfeatures. The device can be otherwise oriented (e.g., rotated 90 degreesor at other orientations) and the spatially relative descriptors usedherein interpreted accordingly.

What is claimed is:
 1. A fluid comprising: an oil; a plurality of carbonnanotubes dispersed within the oil and each having a diameter between 1nanometer and 80 nanometers, wherein at least 0.76 percent of theplurality of carbon nanotubes have OH functionalized surfaces; and aplurality of boron nitride particulates dispersed within the oil,wherein each of the plurality of boron nitride particulates are separatefrom each of the plurality of carbon nanotubes and have an averageparticle size between 50 nanometers and 90 nanometers; and wherein aconcentration of the plurality of carbon nanotubes is between 0.08 gramsand 0.4 grams per 946 milliliters of the oil and wherein a concentrationof the plurality of boron nitride particulates is between 0.08 grams and0.4 grams per 946 milliliters of the oil.
 2. The fluid of claim 1wherein at least some of the plurality of carbon nanotubes aremulti-walled carbon nanotubes.
 3. The fluid of claim 1 wherein anaverage length of the plurality of carbon nanotubes is between 1 micronand 1000 microns.
 4. The fluid of claim 1 wherein the boron nitrideparticulates are hex-boron nitride, cubic boron nitride or wurtziteboron nitride particulates.
 5. A concentrate comprising: a fluid; aplurality of carbon nanotubes dispersed within the fluid, wherein eachcarbon nanotube of the plurality of carbon nanotubes has a diameterbetween 1 nanometer and 80 nanometers and wherein at least 0.76 percentof the plurality of carbon nanotubes have OH functionalized surfaces;and a plurality of boron nitride particulates dispersed within thefluid, wherein each of the plurality of boron nitride particulates areseparate from each of the plurality of carbon nanotubes, and wherein theplurality of boron nitride particulates have an average particle sizebetween 50 nanometers and 90 nanometers; and wherein the concentrate isconfigured to be mixed with a predetermined quantity of oil such thatthe mixture of the predetermined quantity of oil and the concentrate hasa carbon nanotube concentration between 0.08 grams and 0.4 grams per 946milliliters of the oil and a boron nitride particulate concentrationbetween 0.08 grams and 0.4 grams per 946 milliliters of the oil.
 6. Theconcentrate of claim 5 wherein at least some of the plurality of carbonnanotubes are multi-walled carbon nanotubes.
 7. The concentrate of claim5 wherein an average length of the plurality of carbon nanotubes isbetween 1 micron and 1000 microns.
 8. The concentrate of claim 5 whereineach of the boron nitride particulates of the plurality of boron nitrideparticulates are hex-boron nitride, cubic boron nitride or wurtziteboron nitride particulates.
 9. An engine oil additive comprising: aplurality of unitary carbon nanotubes each having a diameter between 1nanometer and 80 nanometers, wherein at least 0.76 percent of theplurality of carbon nanotubes have an OH functionalized surface; and aplurality of unitary boron nitride particulates having an averageparticle size between 50 nanometers and 90 nanometers; wherein theadditive is configured to be mixed with a predetermined quantity ofengine oil such that the mixture has a carbon nanotube concentrationbetween 0.08 grams and 0.4 grams per 946 milliliters of the engine oiland a boron nitride particulate concentration between 0.08 grams and 0.4grams per 946 milliliters of the engine oil.
 10. The engine oil additiveof claim 9 wherein at least some of the plurality of carbon nanotubesare multi-walled carbon nanotubes.
 11. The engine oil additive of claim9 wherein an average length of the plurality of carbon nanotubes isbetween 1 micron and 1000 microns.
 12. The engine oil additive of claim9 wherein each of the boron nitride particulates of the plurality ofboron nitride particulates are hex-boron nitride, cubic boron nitride orwurtzite boron nitride particulates.